Cut-in system of radiotelegraphy



Aug. 31 1926.

CUT

1598,22? P. WARE -IN SYSTEM OF RADIOTELEGRAPHY Original Fild Feb. a. 1918 rill Patented Aug. 31, 1926.

rear ear.

PAUL WARE, OF NEW YORK, N. Y., ASSIGNOR TO WARE RADIO, INU, OF NEW YORK, N. Y., A CORPORATION OE DELAWARE.

CUT-IN SYSTEM G13 BABIOTELEGRAPHY.

Original appIication filed February 8, 1918, Serial No. 215,986, Patent No. 1,379,144.

application filed April 14, 1921.

This invention relates to radio telegraphy and has for its object to increase the rapidity with which tratfic may be handled by enabling the receiving station to cut in on the sending station at will and without disturbing the adjustments of the system.

Much delay is now caused in radio telegraph communication because the receiving operator must wait until the sending operator has signed off before he can communicate with the sending operator. By this invention, the receiving operator can cut in on the sending operator at any time, so that it becomes unnecessary for the receiving operator to wait until the sending operator hassigned oif and has put his apparatus in condition for receiving, and the receiving operator has put his apparatus in condition for sending, before reversing the direction of communica tion. This invention is especially adapted for undamped wave transmission the beats method, wherein the frequencies of the sending and receiving stations differ to such extent thatbeats are produced at the receiving station. In present methods of radio telegraphy by the beats method, the sending operator does not know either whether his signals are being sent out from his station, the character of his sending, or whether they are being received at the other end, which is the reason for much of the delay above referred to, but with this invention the telegraph signals are heard at both ends.

According to this invention, a station is provided having a single antenna both for receiving and sending, in conjunction with de tecting means for incoming signals separate from the means for producing outgoing oscillations, together with a sending key so as to control the outgoing oscillations and atthe same time to permit of effecting a cut-in upon movement thereof.

In normal operation of a station embodyinga preferred form of this invention, there is continuously produced a local oscillation which in combination with the incoming oscillations produces a beat notein the receiving system. Interruption of the incoming oscillations, as by a key at another station interrupts the beat note and thus produces the signal, while at the same time such a receiving station radiates oscillations which are received at the other station and Divided and. this Serial No. 461,437.

fecting a cut in from a receiving to a sending station wherein the receiving station embodies a single radiating and collecting element and a means for producing local oscillations in the receiving portion of the circuit separate from the source producing outgoing oscillations to be received by the other station. The circuit may also be adjusted however so that the sending oscillations form ieats with the incoming to form the receiving signalling current. i

The accompanying drawing shows in diagram a form of'apparatus embodying the invention, adapted for medium to long distance communication wherein it is desired to have the outgoing oscillations of greater strength than can be readily obtained where the same element produces the local oscillations and at the same time detects and amplifies the incoming waves. As herein shown the sending circuits are so arranged that the relatively powerful transmitted energy does not interfere with the receiving circuits.

1 represents an antenna connected to divided adjustable inductances 2, 3, through adjustable condenser 4t and resistance 5 to ground 6. From wire 7 connecting inductances 2, 8, a wire 8 leads to the bottom contact 9 of key 10 having upper front contact 11 and back contact 12. From contact 11 a wire 13 leads through adjustable condenser 14 to the ground wire.

From the bottom contact 15 on the key 10 wire 16 leadsto wire 17 of the receiving circuit which is itself connected to the grid 18 of oscillator 19, which as herein shown consists of a vacuum tube. 20 is the plate connected by wire 21, and through inductance 22 to plate battery 23 which is in series with telephone receivers 2 1 and thence connected by wire 25 to filament 26, of tube 19. The other end of the filament is connected through filament resistance 27 and filament battery 28 to Wire 29. Connected between wire 29 and wire 17 is receiving inductance 30. Connected across receiving inductance 30 is adjustable tuning capacity 31 for tuning the receiving circuit to the incoming signal.

From contact 12 the Wire 32 is connected through adjustable condenser 33 to Wire 29. l/Vhen key 10 is down, closing contacts 11 and 9, condenser 33 is open circuited, and the receiving system in correct tuning for heterodyne reception, but When the key is up and the circuit 12,15, 16, 32, is closed, condenser 33 is shunted across the tuning condenser 31 thereby throwing the receiving system suficiently out of tune with the incomin signal as to destroy the beat note.

In send-ing, he wave length, and consequently the beat note, is varied by placing the condenser 14inand out of shunt across antennasending inductance .34 at contacts 9, ll The sourceof sending oscillations is tube 35, wherein the plate 36 is connected by wire 37 to inductance 38 "which is coupled to, inductance 34 and thence by wire 39 to plate battery 40, ammeter-41 to wire 42. 43 is a filament battery, 44adjustable resistance, 45 the filament, 46 is agrid connected by wire 47 to inductance 48 also coupled to in ductance v34 and thence by wire 49 to grid battery 50 and Wire 42. p p

The sendingapparatus is consequently so arranged that the transmitted energy from tube does noteffect the receiving system. This is done by coupling the receiving inductance 30 to the divided antenna inductance 2, .3, in such manner that the Wire 8, connected between inductances 2, 3,, carrying the sending energy, balances same out in inductances 2, 3, so that it has no effect upon receiving inductance 30. Thus the sending energy'is balanced on one side of inductance 30 by in ductance 3, condenser 4 and resistance .5;

and on the other side, by antenna inductance,

capacity and resistance above the point of connection of wire 8 to antenna inductances z o The power of the outgoing oscillat ons can thus be made'relatively very strong as compared with that of the incoming oscillations so as to give considerable distanceof communication, without interfering with reception, while using a single radiating and receiving antenna. lVhen a station of this character is used in connection with another stationthey will ordinarily be arranged-so that when both keys are in like position, as down, each station has a beat note audiblein the receivers 24 produced by the combination of the local oscillations with the incoming receiving oscillations, each operator hearing the beat note at his station. operator sends by actuating his key in the usual manner, thus hearing his own telegraphing and the receiving operator receives by holding his key down, according to usual practice on wire lines. hen the receiving The sending operator desires to cut in he lifts his key, which interrupts his own beat note and also that at the other station, thus effecting the signal, whereupon the sending operator Will hold his key down to receive what the otheroperator desires to send by actuating his key in the usual manner.

It will be understood that instead of telephone receivers any other suitable form of signal indicating device may be used, and other specific circuits from that herein disclosed for detecting and amplifying, as well as-other means for preventing the sending energy from interfering with reception, may be employed. It will a-lso'be understood that I do not confine myself to any specific way of varying the beatnote, Whether by producing a beat note out :of audibility range, or one ofdiiferent pitch, or suppressing the beat note --entirelywhether in or out'of audibility range, nor am I to be understood as restricting the term beat note to one which is audible, as I intend said term to cover the oscillations resulting from heterodyning oscillations of different frequencies, and directly or indirectly detecting such beat note. By this invention the speed of possible communication in radio telegraphy is made equal to that of land'wire ,telegraphy, by keys operating in the manner customary with land wire telegraphy, which so faras I am aware has not heretofore been :done.

Various modificationsfand changes may be made Without departing fronrthescope of the appended claims.

This application is a division of my application. filed February 8, 1918, Ser. No. 215,996, patented May 24, 1921, #1,379,144.

lVhat I claim is: i I I 1. The methodof effectingtwo Way span radiotelegraphywhich consists in separately producing ateach of two stations outgoing and receiving oscillations of different frequency, transmitting the outgoing oscilla-.

tions and receiving the incoming oscillations at each station in a manner to produce signal oscillations at, each station by the resultant of the incoming and receiving oscillations without afifecting the received by the outgoing oscillations, detecting such signal oscillations at'each station to produce an in.- dication, and varyingthe outgoingand receiving oscillations at one station toeifect asignal at both stations by variation of both signal oscillations.- I

2. A space 'radiotelegraph system comprising a plurality of stations each' having a single antenna, separate sources of outgoing and local receiving oscillations coupled thereto, there being such difference in the received and local oscillations at each station as to continuously produce local signal oscillations at each station, meansfor indicating said signal oscillations, and akey at each station controlling both signal oscillations in such manner that said oscillations are locally manifest only When the keys are in like positions, whereby to permit sending from one station and cut in from the receiving station upon actuation of each key respectively.

3. A space radiotelegraph system compris ing a plurality of stations each having a single antenna, separate sources of outgoing and local receiving oscillations coupled thereto, means for preventing the outgoing oscillations from affecting the received oscillations, there being such dill'erence in the received and local oscillations at each station as to continuously produce local signal oscillations at each station, means for indicating said signal oscillations, and a key at each station controlling both signal oscillations in such manner that said oscillations are locally manifest only when the keys are in like positions, whereby to permit sending from one station and cut in from the receiving station upon actuation of each key respectively.

l. A space radiotelegraph system comprising a plurality of stations each having a single antenna, separate sources of outgoing and local receiving oscillationscoupled thereto, means for balancing the outgoing oscillations so as not to ailect the receiving means, there being such difference in the received and local oscillations at each station as to continuously produce local signal oscillations at each station, means for indicating said signal oscillations, and a key at each station controlling both signal oscillations in such .nanuer that said oscillations are locally manifest only when the keys are in like positions, whereby to permit sending from one station and cut in from the receiving station upon actuation of each key respectively.

5. In radio telegraphy, a plurality of stations each employing the same antenna for both sending and receiving, a signal sending key at each, means for producing outgoing oscillations and separate means for detecting incoming oscillations, means for preventing the outgoing oscillations from paralyzing the receiving means, the receiving as Well as the transmitting means being controlled from the signal sending keys in such manner that normal signal receiving is had when the key is in position for normal signal sending.

6. In a radio telegraph system employing a common radiating and collecting element, means for selectively producing outgoing oscillations on diiilerent frequencies, means for selectively producing receiving oscillations on different frequencies to be combined With incoming oscillations, means for detecting the incoming oscillations, means for balancing the outgoing oscillations so as not to atfeet the detecting means, and control means for both of said producing means adapted to permit the simultaneous change in frequency oi" the outgoing and receiving oscillations.

7. A radio station employing the same antenna for sending and receiving, means for producing outgoing oscillations, a separate receiving system, means for preventing paralysis of the receiver, signal controlling means, and means whereby the operator in sending signals can hear his own signals and receive a cut-in signal from another station at the will of the operator at that station.

8. An undamped wave radio telegraph station en'iploying means for receiving 1ncoming and transmitting outgoing oscillations simultaneously on the same antenna, means for detecting and indicating incoming oscillations, means for making receiver selective to incoming oscillations, the indication of incoming oscillations being controllable from sending key so as to be evident only when the key is in sending position.

9. A radiotelegraph circuit employing a common radiating and collecting element, receiving and relatively powerful transmitting means connected thereto in such a man her as to afiord simultaneous radiation and reception, and a transmitting key controlling the receiving means in such manner that incoming signals can only be normally detected when the key is in normal position for sending signals. 7

Signed at New York, in the county of New York and'State of New York, this eleventh day of April, A. D. 1 921.

PAUL W ARE. 

